It was meant to be a private gesture, but the New York policeman who bought a homeless man a $100 (£62) pair of boots has won international and official praise.

Officer Larry DePrimo appeared before throngs of reporters and cameras on Thursday after being awarded a pair of cufflinks by his boss, NYPD Commisioner Ray Kelly.

The 25-year-old explained that he had been inspired by his grandfather to buy the anonymous barefoot man a pair of shoes, after encountering him during his beat near Times Square on a cold evening in early November.

"He told me when I was much younger, 'If you are going to do something, do it 100%. And do it, or don't do it at all,'" Officer DePrimo said.

"I didn't really think anything of it at the time," he added. "What sticks out in my mind is he was such a kind gentleman that I had to help him. I wanted to."

Larry DePrimo's family home in Suffolk County, where the officer lives in a basement apartment, was also besieged by satellite trucks and journalists.

And both he and the tourist who secretly snapped the photo - a civilian police worker from Arizona - were doing the rounds of US breakfast TV shows on Friday.

Jennifer Foster posted the image to the NYPD's Facebook Page and kicked off the internet phenomenon which has seen millions viewing the story and thousands of 'likes' and positive comments.

But amid all the praise, there has been inevitable cynicism and some concern for the unidentified man at the centre of the modern-day fairytale of New York.

"I walked by this man in Union Square Wednesday, November 21," wrote Melissa Gallaher-Smith. "And he was again barefoot. I remember very clearly because his pants were also hiked up and his feet were very large."

Several others reported seeing the same man - always without shoes. One told how she had bought a pair for him on a previous occasion, leading to speculation among others that he may be working some kind of scam.

Homeless charities also waded in, praising Officer DePrimo's actions but pointing out it is not in line with the NYPD's usual treatment of vagrants.

Patrick Markee, from the Coalition for the Homeless told the LA Times that successive New York mayors had sought to clean the city's streets of rough sleepers.

"It was a really moving photo and a moving story," he said, "and a stark contrast to a mayor who has largely ignored the homeless crisis that has spiralled out of control on his watch."

Whatever the truth of the situation, others argue, it does not detract from the young officer's caring and inspirational gesture.